storm surge that could top out at ten feet. extreme conditions could begin as early as sunday and last for days, drenching the most populated part of the country. >> this storm, that is going to be impacting the mid-atlantic and parts of the northeast monday into tuesday is going to be destructive, historic and, unfortunately, life threatening. >> reporter: a state of emergency has already been declared in maryland, d.c., pennsylvania, new york and virginia. the biggest fear? the storm surge. in places like atlantic city, it could get even worse because of a full moon and higher tides. people are batoning down the hatches, preparing for the worst, up and down the eastern seaboard. in norfolk, the navy ordered 23 ships to leave port immediately. on the jersey shore, people are stocking up on essentials, including those generators. and in new york city, major bloomberg warned he may have to shut down the subway because it might flood.